Deicing means for propellers



Nov. 23, 1943. E; w. MORRIS HAL 2,335,018

u DEIGING MEANS FOR PROPELLERS Filed Deg. 9, 1939 2 Sheets-Sheet 1 INVENTORS EDWARD NMORRAM fiC/f HJHEETJ ATTORNEY Nov. 23, 1943. E, w) MORRIS ET AL 2,335,018

DEICING MEANS FOR PROPELLERS Filed D86. 9, 1939 2 Sheets-Sheet 2 INVENTORS A E DIVA/PD M MORRIS &.MCK If. 5/155 75 ATTOR N EY'..

I Patented Nov. 23, 1943 Edward w. Morris, Tipp City, 01116, and Jack a.

. Sheets. Hawthorne, N. J., assignors to Curtiss- Wright Corporation, a corporation of Delaware Application December 9, 1939, Serial, No. 308,454

1 Claim. (01. 244-434) Thisinvention concerns aeronautical propellers, and in particular provides means for prev venting the formation of ice on the blades of propellers whose pitch is adjustable during operation.

' It is known that the problem of ice formation. on propeller blades has been considered hereto-- fore with particular reference to fixed pitch propellers. It is an object of this invention to provide de -icing means for controllable propellers, the invention providing for the feeding of de-icing fluid from stationary parts of the system to the rotating propeller in such manner that the fluid is fed regardless of the position of pitch adjustment. A further object is-to provide a particular conduit construction for hollow .propeller blades by which de-icing fluid is conducted to the leading edges of propeller blades. Still a further ob- Ject is toprovide means for feeding de-icing fluid to the leading edge of a cut! or fairing which embraces the root portions of a propeller blade.

Further objects will be apparent from a reading of the subjoined specification and claim, together with an examination of the accompanying drawings, in which:

Fig. 1 is a side elevationoi a controllable pitch aeronautical propeller mounted upon the nose of an engine, the propeller incorporating the provisions of the invention;

Fig. 2 is a section through a blade of the propeller on the line 2-2 of Fig.8;

Fig. 3 is a longitudinal section through one of v the propeller blades;

Fig. 4 is an enlarged section on the line 4-3 Fig. 1:

Fig. 5 is a fragmentary elevation of a moimted propeller blad sh owing a fairing cuff in section,

and

ceive a screw abutment which coopertes with the hub bearing assembly. Within the hollow of the blade I, at its leading edge, a small tube I9 'is secured as by brazing, the brazing fillet being indicated at 20. At spaced apart intervals along the blade leading edge small holes M are formed these being drilled through the leading edge of r the blade and through one wall of the tube I! to allow of the issue of fluid fed to the tube I9 at the blade butt to theoutside of the blade surface for the purpose of dissolving icewhich may form thereon during operation. A suitable fluid might comprise alcohol, glycerine or the like.

is secured around the blade bu 1; comprising elements 24 and 25 hinged at 8 and secured to the blade by a clamp bolt 21. Theelement 24 is provided with a'segmental passage or conduit 28 communicating at one end with the drilling 22 and at its other end with a, drilling 30 opening to an inwardly facing segmental trough 3| formed in a segmental boss 32 integral with the element 23. The segmental trough 3| is concentric with the butt portion of the blade and has an arc of embracement substantially equal to the angular Fig. 6 is an enlarged section on the line '88 of Fig. 5.

Referring to Fig. 1, a propeller hub I I carrying a power unit II and a speed reducer I! at its forward end, is drivably mounted upon a shait extending from an engine nose 13, the elements I I and I2 serving to selectively increase or decrease, the pitch of the propeller blades, one of which is shown at H, in a manner well known in the art- The blades are rotatably mounted in the hub onthrust bearings, also known to the art, and the particular type of blade shown comprises a hollow shell of steel or other suitable material, having a cross-section as indicated in Fig. 2. The root portion of the blade, shown at II in Fig. 3. is cylindrical in form and is provided with an integral flange ii the butt oithe pitch change in the blade which may be expected during operation. To the propeller hub and rotatable therewith issecured an annulus 34 having a catch slot 3! and provided with radiallyextendingnozzles 38, each of which lies opposite one of the troughs 3 I. Secured to the engine nose is a pipe line 33 through which de-icing fluid is fed from a suitable reservoir, this tube terminating in a nozzle 38 directed into the catch slot 35.

In operation, when fluid is fed through the tube 33 it is delivered to the catch slot 35 whence it passes through the nozzles 36 into the grooves ll of the propeller blades. Since the annulus 33 is rotating rapidly with thepropeller hub, the de-icing fluid. is thrown by centrifugal force through the nozzles 33 and into the grooves 3| whence it passes through. the conduits described to the leading edge ofthe propeller blade.

In some types of propellers, the blades tend toward a circular cross-section at their root and to endow them with greater aerodynamic'efflciency. a sheet metal cufl or fairing maybe clamped to the blades. Such a cult is shown in Figs. 5 and 33 at 43. These cufls extend possibly blade being interiorly threaded as at nto refie one-quarter of the blade length from the hub, and on propellers equipped with the cuifs eiiectlve de-icing may be attained by flt'ting a de-icing In order to feed de -icing fluid to the blade, an inlet drilling 22 is formed through the blade butt radially inward of the flange I6,'and a fitting 23 ends, we

fluid conduit to the leading edge of the cuff 40 whence de-icing fluid sprays substantially radially outward along the balance of the propeller blade to prevent the formation of ice thereon. In applying the invention to propeller cuffs, the conventional forging 4| which forms the base for the crfl replaces the assembly 23 above described and carries a segmental portion 32' having a segmental trough 3| for reception of deicing fluid. A passage 28' in the forging 4| conducts de-icing fluid toward the leading edge of the cuff whence it issues to a tube 42 brazed to the inside of the leading edge portion of the cuff. Drillings through the cuff and one wall of the tube permit the flow of fluid to the leading edge of the cuff for de-icing purposes. The cufi, incidentally, is rigidly secured to the forging 4| which may be passed over the cylindrical butt end of the propeller blade before assembly of the blade in the hub, the member 4| abutting upon the flange IE to constrain it against displacement due to centrifugal force. The outer end of the icufi' conforms in general to the profile oi the propeller blade at that station, but is in clearance relation thereto, the clearance space being filled with a soft resilient material such as rubber or leather, such gasket being shown at 44. This gasket prevents abrasion of the polished surfaces of the propeller blade.

The tube 42 may be extended as at 45 through the outer cuff edge to form a nozzle to spray de-- icing fluid along the leading edge of the blade l4 in addition. to feeding fluid to the cuff leading I edge. Although a sheet metal cufl has been shown, the invention is intended to cover deicing provisions for cufls and blades of any material.

The means for feeding the segmental trough 3| is the same as that shown in Fig. 1, comprising the'annulus 34 having a catch slot 35 and nozzles '36, the catch slot being fedfrom a nozzle 39 at the end of the fluid conduit 38 secured'to the engine.

Whilewe have described our invention in detail in its present preferred embodiment, it will be obvious to those skilled in the art, after understanding our invention, that various changes and modifications may be made therein without departing from the spirit or scope thereof. We aim in the appended claim to cover all such modiflcations and changes.

We claim as our invention: a

In a propeller blade having a substantially cylindrical butt end, a member embracing said end having a conduit therein extending from a point'substantially alined with the blade leading edge to a point adjacent the extreme rear of the blade, means at said first point to convey deicing liquid therefrom toward the blade leadingedge, an open, inwardly facing recess at said second point to receive de-icing fluid, and a streamlined fairing secured to said embracing member and extending outwardly therefrom to embrace the cylindrical portion of'the blade.

EDWARD W. MORRIS. JACK H. SHEETS. 

